Philip W. P. Bearcroft

MR-guided direct arthrography of the glenohumeral joint.

AIMnTo evaluate the feasibility of magnetic resonance (MR)-guided direct arthrography of the glenohumeral joint with a 1.5 T MR system, performing the entire procedure in a single MR examination.nnnMATERIALS AND METHODSnMR-guided direct arthrography was performed on 11 patients. MR imaging guidance and interactive MR fluoroscopy, with in-room control and display system, were used for needle placement and contrast medium injection. The outcome measures were success or failure of joint puncture, the time taken for introduction of contrast medium, and the diagnostic quality of the subsequent MR arthrography images.nnnRESULTSnContrast medium was successfully instilled into the joint and diagnostic quality MR arthrography images were obtained in all cases. The median time from initial placement of the skin marker to introduction of the contrast medium was 17 min (range 11-29 min). There were no immediate post-procedure complications.nnnCONCLUSIONnAccurate needle placement is feasible in a single MR examination on a commercial 1.5 T closed-bore MR system, using an in-room control and display system together with interactive fluoroscopic imaging, and this was used to provide direct MR arthrography in this study.

CT of the musculoskeletal system: What is left is the days of MRI?

Magnetic resonance imaging (MRI) plays a central role in the modern imaging of musculoskeletal disorders, due to its ability to produce multiplanar images and characterise soft tissues accurately. However, computed tomography (CT) still has an important role to play, not merely as an alternative to MRI, but as being the preferred imaging investigation in some situations. This article briefly reviews the history of CT technology, the technical factors involved and a number of current applications, as well as looking at future areas where CT may be employed. The advent of ever-increasing numbers of rows of detectors has opened up more possible uses for CT technology. However, diagnostic images may be obtained from CT systems with four rows of detectors or more, and their ability to produce near isotropic voxels and therefore multiplanar reformats.

MR-guided direct arthrography of the hip.

To develop an MR‐guided technique for direct magnetic resonance arthrography (DMRA) of the hip using a conventional 1.5 Tesla (T) MRI scanner.

Giant atypical ossifying fibromyxoid tumour of the calf

We present a case of giant atypical ossifying fibromyxoid tumour (OFMT) of soft tissue, occurring in the calf, in a 77-year-old woman. The patient presented with a history of bleeding ulcer over a calf lump that had been present for over 4 years. Clinical presentation, radiological features and histopathologic findings are described, and the relevant literature is reviewed.

Validation of clinical examination versus magnetic resonance imaging and arthroscopy for the detection of rotator cuff lesions

Limited evidence exists regarding the validity of clinical examination for the detection of shoulder pathology. We therefore wished to establish the sensitivity, specificity, positive predictive value and negative predictive value of clinical tests and magnetic resonance imaging (MRI) in the diagnosis of rotator cuff disorders against findings at arthroscopy. Using recognised tests for specific shoulder lesions, 117 patients with shoulder symptoms awaiting surgery were examined in a standard manner. The diagnoses were categorised and compared with abnormalities found on MRI and at surgery. Results were cross-tabulated to determine the above parameters. Ninety-four patients formed the study group with a mean age of 51xa0years. The median duration of symptoms was 45xa0weeks. For clinical examination, sensitivity and specificity to detect a tear or rupture of supraspinatus were 30xa0% (16/54) and 38xa0% (15/40) and, for the detection of any pathology, were 94xa0% (67/71) and 22xa0% (5/23), respectively, compared with arthroscopy. Correspondingly, the sensitivity of MRI compared with arthroscopy to detect a tear or rupture of supraspinatus was 90xa0% (28/31) with a specificity of 70xa0% (46/53), whereas for the detection of any abnormality, the sensitivity was 92xa0% (65/71) with a specificity of 48xa0% (11/23). The sensitivity of detecting any rotator cuff abnormality is high when examination and MRI is compared with arthroscopy with the specificity being greater with MRI than examination. In patients with shoulder symptoms severe enough to consider surgery, clinical assessment followed by specific imaging may help define the pathology in order to direct appropriate management.

The reliability of measuring the density of the L1 vertebral body on CT imaging as a predictor of bone mineral density

AIMnTo determine whether the density of the L1 vertebra measured on computed tomography (CT) images correlates with the bone mineral density (BMD) as measured by quantitative computed tomography (QCT), and to determine the reliability of L1 density measurements by different observers to see if this measure could help identify patients who would benefit from formal BMD assessment.nnnMATERIALS AND METHODSnNon-contrast CT along with a phantom for determination of BMD was performed on 30 healthy patients. The L1 density was measured by 3 observers at two time-points separated by at least 2 weeks.nnnRESULTSnL1 density was well correlated to the QCT BMD (correlation coefficient 0.83; 95% confidence interval [CI]: 0.67-0.92). There was excellent intra- and interobserver agreement in L1 density measurements. There were excellent intra-class correlation coefficients for each observers measurements at two separate time points with a coefficient for observer 1 of 0.94 (95% CI: 0.88-0.97) and for observer 2 and 3 of 0.99 (95% CI: 0.98-1). The interobserver measurements had an intra-class correlation coefficient of 0.98 (95% CI: 0.96-0.99).nnnCONCLUSIONnL1 vertebral density can be reliably measured on CT images and might be used as an indicator of BMD for opportunistic screening of patients with osteoporosis. Low bone density detected incidentally on CT imaging could be used to identify patients who should be further investigated and treated for osteoporosis.

Soft-tissue masses in the shoulder girdle: an imaging perspective

We discuss the radiological assessment of soft-tissue masses presenting in the shoulder girdle and emphasise the relative strengths and weaknesses of the different imaging modalities available. The appearances of the common benign and malignant soft-tissue tumours are presented together with conditions that present with specific imaging features around the shoulder region.

The normal ischiofemoral distance and its variations

The aim of this study is to measure the ischiofemoral distance (IFD) in the normal hip with healthy surrounding soft tissues and describe its variations caused by gender, age and proximal femoral anatomy so that this could serve as a reference for future studies on this subject. This is a retrospective study in which we reviewed the CT scans of 149 patients (298 hips) who had a CT of their pelvis for non-orthopaedic (abdomino-pelvic) pathology. The images were reviewed by two independent observers and the IFD (the smallest distance between the lateral cortex of the ischial tuberosity and the posteromedial cortex of the lesser trochanter), offset (the perpendicular distance from the centre of the femoral head to a line running down the middle of the shaft of the femur) and the neck-shaft angle (the angle between the lines in the middle of the neck to the line forming the axis of the femoral shaft) were measured. The CT scans belonged to 71 males and 78 females (M: 48%, F: 52%), with an average age of 51 u2009± 19 years (range 18–92). The mean IFD was 18.6 u2009± u20098u2009mm in the females and 23 u2009± 7u2009mm in the males and this difference was statistically significant (P < u20090.001). The IFD increased by 1.06u2009mm for each 1u2009mm of offset and dropped by 0.09u2009mm with each year of age. However, the neck-shaft angle did not show any significant correlation with the IFD.

L1 vertebral density on CT is too variable with different scanning protocols to be a useful screening tool for osteoporosis in everyday practice

OBJECTIVEnTo determine whether a single L1 density threshold can be used to screen all patients undergoing CT at a busy tertiary referral centre for those at risk of osteoporosis.nnnMETHODSn200 patients, who had been randomly selected for an audit of CT reporting of incidental vertebral fractures, had their L1 density measured on 864 routine CT examinations. These had been performed with a variety of kVp and intravenous (i.v.) contrast protocols, reflecting the wide range of imaging indications.nnnRESULTSnL1 density measured on thick axial, thin axial or sagittal images had an excellent intraclass correlation coefficient (0.996). For the same patients imaged twice within 6 months, there was mean intraexamination L1 density difference of 27.5 HU. Variability due to i.v. contrast medium administration resulted in a mean difference of 24.5 HU. Mean difference due to acquisition kVp was 24.1 HU. Once matched for sex, age, kVp and i.v. contrast, there was a significant difference between the L1 density in patients with vertebral fractures compared to those without fractures (mean 30.19 HU).nnnCONCLUSIONnThere is significant variability in the L1 vertebral body CT density due to differences in acquisition variables such as kVp and timing post-i.v. contrast medium. Advances in knowledge: Previous studies suggested that L1 CT density could be used to screen for osteoporosis. The current study cautions that it is not possible to define a single L1 density threshold for screening, due to the number of variables within a wide range of scanning protocols for different imaging indications in everyday practice.